Conventional electroless deposition of metals such as copper on a substrate use inorganic alkali metal hydroxides to basify the reaction and provide high hydroxyl ion concentrations needed for the reduction of the metal ions. Electrical components prepared from such components suffer from the disadvantages resulting from residual alkali metal in the deposited metal layer.
The present invention eliminates the alkali metal contamination by formulating the electroless compositions in an alkali-free environment to prevent alkali metal penetration into the silicon dioxide and microelectronic components.
The terms "free of alkali metal" and "substantially free of alkali metal", used interchangeably herein, mean that the ingredients used to formulate the electroless deposition composition either do not contain alkali metal elements or compounds or are present therein in trace amounts (less than 1 ppm).